diff --git a/.github/workflows/test_cluster.yml b/.github/workflows/test_cluster.yml
index 13de700..f4be8e2 100644
--- a/.github/workflows/test_cluster.yml
+++ b/.github/workflows/test_cluster.yml
@@ -33,8 +33,9 @@ jobs:
       fail-fast: false
       matrix:
         distro:
+          - ubuntu-18.04
+          - ubuntu-20.04
           - ubuntu-22.04
-          - ubuntu-23.04
           - debian-11
           - debian-12
           - fedora-38
diff --git a/.github/workflows/test_cluster_mdbf.yml b/.github/workflows/test_cluster_mdbf.yml
index 209ad02..550f039 100644
--- a/.github/workflows/test_cluster_mdbf.yml
+++ b/.github/workflows/test_cluster_mdbf.yml
@@ -33,8 +33,8 @@ jobs:
       fail-fast: false
       matrix:
         distro:
+          - ubuntu-20.04
           - ubuntu-22.04
-          - ubuntu-23.04
           - debian-12
           - fedora-38
           - almalinux-8
@@ -47,10 +47,6 @@ jobs:
           - "11.1"
           - "11.2"
         exclude:
-          - distro: ubuntu-23.04
-            mariadb-version: 10.6
-          - distro: ubuntu-23.04
-            mariadb-version: 10.10
           - distro: debian-12
             mariadb-version: 10.6
           - distro: debian-12